Hope VI Residents Deserve Green Housing

Affordable, Healthy Home Design Choices

Top Ten Priorities for Low Utility Bills

• Orientation• Roof color and material• Wall color• Minimizing window area• But allowing for adequate

ventilation

• Minimize carpet, use stamped concrete, tile, or terrazzo

• Properly size AC systems• Install ductwork within

conditioned space• Efficient Water Heating

Systems • Efficient lighting and

appliances

Orientation

Orientation Matters

Roof Color and Material

Attic Temp: 1380F Attic Temp: 1000F

Roof Color and Material

Roof Color and Material

Roof Color and Materials

White metal roof home performed the best(25% measured savings)

Wall color

• No cost associated with selecting a whiter wall color

• Reducing the solar absorbance from 0.8 to 0.5 or from 0.5 to 0.3 can save 3 to 5% of the heating/cooling bill.

Minimizing Window Area

Window Shading Strategies• Minimize East and West Exposures• Use Overhangs on all Sides –Particularly

South• Plant Shade Trees• Exterior Awnings or Bahama Shutters• Interior Shades• Low SHGC Glass or Films

Window Shading Strategies

Window Strategies

Allow Adequate Ventilation• Provide cross-through ventilation from front to

back and side-to-side• Make sure all windows are operable and have

durable, easy-to-use hardware• Provide openings on two different walls in each

bedroom• Bedroom ventilation may work best on 2nd story• Space buildings to avoid blocking breeze

Natural Ventilation

• Ideally, window openings should equal 12% of floor area

Allow Adequate Ventilation

• Augment with whole house fans

• Include ceiling fans

• Have outside rooms open on three sides

Whole House Fan

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Without fan With fan

KitchenLiving RoomOutside

oF

Minimize Carpet• Use stamped

concrete, tile or terrazzo

• Slight benefit for cooling energy use

• Reduce allergy effects of dust mites

Install ductwork within conditioned space

• Must be incorporated from the beginning of the design phase by architect.

• Save 10 to 20% on heating & cooling

• Reduce uncontrolled airflow and related indoor air quality problems.

Properly Size AC Systems• Typical contractors oversize systems• Installing a three-ton system where a two-

ton system will suffice results in a 10% energy penalty

• Smaller systems work better on humid nights.

• Choose a SEER 13 or better unit.

Use solar or heat pump water heating systems

• Water heating is a much larger portion of the energy bill in most low-income households. Smaller space with more occupants results in less HVAC than average household, but more water heating.

Solar Water Heating

Solar Weatherization Program: Detailed Monitoring of 30 sites$250/year on hot water before solar, $120 after

Solar Water Heating

Efficient Appliances and Lighting Strategies

• Appliances– Energy Star Refrigerator and Washing Machine– Efficient Clothes Dryer

• Lighting– Day lighting (orientation, interior colors)– Efficient bulbs and fixtures

Clothes Washers

horizontal-axis washers use 1/3 less water

Water Conservation

• Indoor– Washing machine and other appliances

Energy Star models use up to 50% less water

Water Conservation• Outdoor

– Xeriscapetm principles can eliminate need for supplemental irrigation after landscape is established.

– If irrigation systems are desired (turf), alternative water sources include greywater, reclaimed water, and rain water collection.

Educate Consumers

• Behavior differences can result in differences in energy bills by a factor of three to 1 for similar size families in similar homes.

Habitat for Humanity Homestead, Fl

Monitored Energy Use

Variation in AC energy consumption

Factors Influencing Variation• Occupant Behavior

– Thermostat Setpoints– Fan Control– Natural Ventilation

• Roofing System– Roof covering– Attic Ventilation– Radiant Barrier

Behavior Variation

Natural Ventilation

Indoor Air Quality

• Source Control– Paints, sealants, and adhesives

• Uncontrolled Air Flow– Can lead to mold and mildew growth– Also affects building durability

Uncontrolled Air Flow

Uncontrolled Air Flow

Uncontrolled Air Flow

Moisture Control

• Dumb Idea#1: Design a building with no slope to the roof

• Dumb Idea#2: Design no overhangs• Dumb Idea#3: Use vinyl wallpaper

Materials• Resource Efficient

– Recycled– Engineered– durable

• Construction Waste Management– Reduce amount of waste– Reduce embodied energy

Statistics• AIA estimates 2 lbs waste/ft2 of new

construction and 60,263 Btu/ft2 embodied energy for wood frame

• Increasing average construction efficiency 4% from 81% for a 1500 ft2 home translates to 120 lbs of waste saved per house and 1059 kWh of embodied energy saved per house.